1. Field of the Disclosure
The disclosure relates to an axial fan, and more particularly to an axial fan providing increased airflow and reduced operating noise.
2. Description of Related Art
With continuing developments in technology, electronic packages such as CPUs (central processing units) generating more heat that requires immediate dissipation. Axial fans are commonly used in combination with heat sinks for cooling CPUs.
Often, an axial fan includes a stator and a rotor. The rotor includes a hub and a plurality of fan blades extending outwardly therefrom. A permanent magnet is arranged in the hub and surrounds the stator. The stator includes a stator core with coils wound therearound. When electrical current is supplied to the coils, the fan blades, rotated by magnetic force of the coils, produce forced airflow. A fan housing surrounding the stator and the rotor guides the forced airflow from one side to an opposite side. However, during operation, while the fan blades rotate, the housing is stationary, and a gap is defined between the outer ends of the blades and the housing to avoid friction therebetween. Accordingly, size of the fan blades is limited, which correspondingly limits airflow. In addition, airflow from the rotary fan blades impacts the stationary fan housing, increasing noise of the axial fan.
For the foregoing reasons, there is a need in the art for an axial fan which overcomes the described limitations.